Abstract: There is provided a sales transaction support apparatus which enables a customer to determine, by his/her own judgment, whether a commodity which may be purchased through a communication sales transaction suits him/her. The sales transaction support apparatus presents a commodity to a user, and provides a try-on simulation image of an object virtually wearing the commodity presented to the user via a network to a terminal device, by using commodity image information of an image of the commodity and object image information of an image of the object. Then, the apparatus executes a transaction process for the commodity.